The synaptic plasticity underpinning long-term memory is associated with the generation of saturated free fatty acids (sFFAs), in particular myristic acid (C14:0), from membrane phospholipids via the phospholipase A1 isoform DDHD2. However, the mechanism through which myristic acid promotes plasticity remains elusive. Myristic acid generated by DDHD2 can produce myristoyl-CoA, a substrate for N-myristoyl transferases (NMT) which can in turn myristoylate synaptic proteins. Here we employ mass spectrometry to show that chemically-induced long term potentiation (cLTP) of mouse primary cortical neurons increased sFFAs and their CoA conjugates (predominantly myristoyl-CoA), an effect largely blocked by the DDHD2 inhibitor KLH-45. We then show specific inhibition of DDHD2 (KLH-45) and down-stream protein myristoylation using the NMT blocker IMP-1088 abrogates cLTP-induced neurogenesis (spine formation) in cultured neurons and field induced LTP in brain slices using electrophysiology. Proteomic investigation in cLTP treated neurons shows a cohort of proteins with correlated dysregulation upon KLH-45 and IMP-1088 treatment indicating the necessity for DDHD2-derived myristic acid to fuel activity dependent protein myristoylation. Further, specific analysis of the myristoylated proteome using mass spectrometry showed post translation myristoylation rather than co-translational N-terminal myristoylation is the driver of this response through regulation of membrane localization of synaptic proteins mediating plasticity.